Electric furnace.



P. T. SNYDER. ELECTRIC FURNACE.-

APPLIOATIOK FILED OUT. 28, 1912.

1 100 995 Patented June 23, 1914.

! JO 9 f W %WM' w zw FREDERICK '1. SNYDER, or oAKPARK, ILLINOIS.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented J ulie 23, 1914;

Application filed ember 2a, 1912. Serial No. 728,090.

ing centrally through said roof.

One of its ob ects is to provide a roofarch or dome of simpleconstruction.

A further object is to provide a removable platform, the standing boardof which is supported at a suflicient distance above the outer surfaceof the roof to prevent said standing board from becoming unduly heated,thus enabling the "workmen to stand upon the platform for the purpose ofadjusting or inserting an electrode through the electrode opening of theroof.

The several features of my invention may be more readily understood byreference to the accompanying drawings, in which-Figure 1 is a central,vertical section through an electric furnace embodyingmy invention; Fig.2 is a top plan view of the furnace shown in Fig. 1; Fig. 3 is aperspective view of one of the electrode bricks which form the crown orkey of the dome; and Fig. 4 is a perspective view of one of the bricksof which the remaining portion of the roofarch is constructed.

Similar letters of reference refer to similar parts throughout theseveral views.

The heating chamber of the furnace is of circular, horizontal section,the upper circular wall 1 thereof constituting the abutment whichsupports the roof arch. The crown of the roof arch is of rectangularcross-section provided with a central electrode opening 2. Said crowncomprises a plurality of tapering bricks 3, the converging corners ofwhich are longitudinally grooved so that when said bricks are assembled,said grooves form the electrode opening 2. The crown of the archpreferably comprises four bricks 3 which are in the form of truncatedpyramids, of square cross section, each having a groove formed in onecorner thereof. Said four bricks, when assembled, form a crown of squarecross-section provided with an electrode hole 2 through the centerthereof.

The roof arch other than the crown thereof is composed of a plurality oftapering bricks 4 having the form of truncatedpyramids, of squarecross-section, said bricks 4 being of such size with respect to thebricks 3 that a given number of the brick 4 will exactly cover the sidesof the crown of the arch. For-example, as shown in Fig. 2, three of thebricks 4 will fit against one of the sides of the crown. In other words,in the structure shown each of the bricks 4 is two-thirds of thethickness of the bricks 3. With bricks so constructed and arranged aroof-arch is formed of simple construction, the crown of whichiiscomposed of interchangeable brick and the remaining portion of the archis also formed of interchangeable bricks which can readily be assembledinto a dome-shaped roof.

By making roof bricks tapering in both directions and arranging them inrows, each brick forms part of two intersecting rows and is thereforekeyed in two directions. This permits any single brick being removed, ifrepairs become necessary, without releasing the adjacent bricks fromtheir other keying arrangement, which latter is transverse to the rowfrom which said brick has been removed. While this form of constructionmakes the roof simple and uniform, it makes an irregular shaped skewbackwhere my form of roof with rectangular rows is used on. a circularfurnace. I therefore provide economical and convenient skewback 6 ofconcrete Which is stamped in place after the roof brick have been placedin osition. This mode of construction avoids the usual expensivechipping of bricks to form a skewback. Preferentially the roof bricksare. made of silica.

It is sometimes desirable that the workmen be able to stand upon theroof of the furnace, either to insert a new electrode through theopening 2 or to make some adjustment of the electrode. It is desirable,in some instances, that this may be done even while the roof of thefurnace is extremely hot. For this reason I provide a roof platformwhich consists of a pair of vertical standards 7 which extend a slightdistance above the upper surface of the roof I and are bent at theirupper ends inwardly toward the center of the furnace. Secured upon theseinward extensions of the standards (is a standing board 8. The standards8 are held insockets 9 so that the roof platform is removable and needbe inserted in place only when required for use.

I In addition to the shell 5, the furnace is smeltin preferably providedabout its roof with an annular ring 10 located inside of the shell 5,and the socket pieces 9 are preferably secured to the innercircumference of the shell 10. Any desired number of roof latforms my beprovided and, in Fig. 2, I ave shown the furnace with four of suchplatforms in position thereon.

The annular ring 10 is removable to permit .the complete roof andplatform being removed for repairs and another ring and new roof beingplacedon the furnace while the first roof is being renewed. I

What I claim is:-

1. In anelectric furnace, the combination with a heating chamber,ofanarch-shaped' roof therefor, omprising a erownportion of squarecross-section composed of a, .plurality of tapering bricks having theirconverging corners ooved to provide in said crown-"an electro e opening,the remaining portionef the roof-arch bemg'composed of tapering brick ofrectangular cross-section the upper end of the circular wall of saichamber constituting an abutment for sai roof-arch.

porting said skewback.

gether, an electrode opening.

4. The combination in an electric furnace, of a roof formed of truncatedpyramids of 40 silica brick keyed together in more than one 7 direction,and a skew-back of concrete.

5. The combination in an electric furnace, of a domed roof formed ofbrick ke .ed in more than one direction, askewbwc supporting said roof,and a metallic. ringsup- In witness whereof, w my name this 26th day ofOctober, A,- -D

j FREDERICK T. SNYDER. Witnesses: Y

Anrnnn H. Moore, MoCLnLmnn YoUNe.

I hereunto subscribes

